Submitted to: Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)
Publication Type: Proceedings
Publication Acceptance Date: 4/18/2007
Publication Date: 6/10/2007
Citation: Trabelsi, S., Nelson, S.O. 2007. Determining Qualtiy Factors of Eggs from Microwave Permittivity Measurements. Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE). Interpretive Summary: The electrical characteristics of agricultural products known as dielectric properties can be useful for rapidly and nondestructively sensing some quality attributes such as moisture content. The dielectric properties of foods are also useful in dielectric or microwave heating applications in the food industry. Some dielectric properties of eggs have been studied in connection with microwave heating for cooking or processing eggs. However, the dielectric properties of eggs have not been explored for purposes of sensing quality. Therefore, some basic measurements were conducted to determine the dielectric properties of egg albumen and egg yolk in the frequency range from 10 to 1800 MHz and to learn what changes in dielectric properties might occur in eggs during storage. Three quality measurements for eggs, the Haugh unit, Yolk Index, and egg weight were also measured for the same eggs in the study. These three quality index values decreased as the eggs were held in storage at 15 degrees C for 5 weeks. Correlations between these quality changes and the dielectric properties over the storage period showed potential for future use of dielectric measurement techniques for rapid assessment of egg quality. Further research is needed to assess the dielectric properties of eggs for potential use in nondestructive quality sensing for benefit of producers and consumers.
Technical Abstract: Dielectric properties of albumen and yolk of eggs were measured at 24 oC over the frequency range from 10 MHz to 1800 MHz to monitor quality changes during a 5-week storage period at 15 oC. Quality factors such as Haugh unit, yolk index, moisture content and egg weight were also measured during the same period. On average, the Haugh unit, yolk index and egg weight decreased with time indicating quality deterioration. Albumen moisture content increased at first and then decreased after the third week of storage. The opposite trend was observed for the yolk moisture content. Correlations between these quality changes and corresponding measured dielectric properties over the storage period show potential for the use of dielectric measurement techniques for rapid assessment of egg quality. Keywords. Eggs, dielectric properties, open-ended-coaxial probe, storage, Haugh unit, yolk index, quality.